Frontiers in behavioral neuroscience
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Front Behav Neurosci · Jan 2014
Environmental enrichment alters protein expression as well as the proteomic response to cocaine in rat nucleus accumbens.
Prior research demonstrated that environmental enrichment creates individual differences in behavior leading to a protective addiction phenotype in rats. Understanding the mechanisms underlying this phenotype will guide selection of targets for much-needed novel pharmacotherapeutics. The current study investigates differences in proteome expression in the nucleus accumbens of enriched and isolated rats and the proteomic response to cocaine self-administration using a liquid chromatography mass spectrometry (LCMS) technique to quantify 1917 proteins. ⋯ The overall impression of the current results is that enriched saline-administering rats have a unique proteomic complement compared to enriched cocaine-administering rats as well as saline and cocaine-taking isolated rats. These results identify possible mechanisms of the protective phenotype and provide fertile soil for developing novel pharmacotherapeutics. Proteomics data are available via ProteomeXchange with identifier PXD000990.
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Front Behav Neurosci · Jan 2014
Nocebo effect in randomized clinical trials of antidepressants in children and adolescents: systematic review and meta-analysis.
To compare the incidence of adverse events between active and placebo arms of randomized clinical trials in depressive children and adolescents (C&A) with antidepressant treatments, in order to look for similarities in both groups that allow to establish a possible nocebo effect. ⋯ Depressive C&A allocated to placebo or active group had similar risk to develop adverse events. These similarities in both groups are attributed to the nocebo effect. It is of note that defining "nocebo" effects is challenging in clinical populations because adverse effects may be attributed to the intervention or may be manifestation of the disease itself. The inclusion of a no-treatment arm may be warranted. Nocebo effects are likely when adverse events of placebo mimic the adverse events of active treatment, as was the case here.
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Front Behav Neurosci · Jan 2014
Comparison of anterior cingulate vs. insular cortex as targets for real-time fMRI regulation during pain stimulation.
Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback allows learning voluntary control over specific brain areas by means of operant conditioning and has been shown to decrease pain perception. To further increase the effect of rt-fMRI neurofeedback on pain, we directly compared two different target regions of the pain network, notably the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC). Participants for this prospective study were randomly assigned to two age-matched groups of 14 participants each (7 females per group) for AIC and ACC feedback. ⋯ Consequently, the ACC and AIC are suitable targets for real-time fMRI neurofeedback during pain perception as they both affect the caudate nucleus, although functional connectivity indicates that the direct connection seems to be stronger with the ACC. Additionally, the caudate, an important area involved in pain perception and suppression, could be a good rt-fMRI target itself. Future studies are needed to identify parameters characterizing successful regulators and to assess the effect of repeated rt-fMRI neurofeedback on pain perception.
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Front Behav Neurosci · Jan 2014
Generalization of fear-potentiated startle in the presence of auditory cues: a parametric analysis.
Intense fear responses observed in trauma-, stressor-, and anxiety-related disorders can be elicited by a wide range of stimuli similar to those that were present during the traumatic event. The present study investigated the experimental utility of fear-potentiated startle paradigms to study this phenomenon, known as stimulus generalization, in healthy volunteers. Fear-potentiated startle refers to a relative increase in the acoustic startle response to a previously neutral stimulus that has been paired with an aversive stimulus. ⋯ In Experiment 1, participants showed similar levels of fear-potentiated startle to the GS that were adjacent to the CS+, and discriminated between stimuli that were 2 or more degrees from the CS+. Experiment 2 demonstrated no fear-potentiated startle generalization. The current study is the first to use auditory cues to test generalization of conditioned fear responses; such cues may be especially relevant to combat posttraumatic stress disorder (PTSD) where much of the traumatic exposure may involve sounds.
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Front Behav Neurosci · Jan 2014
Partial genetic deletion of neuregulin 1 and adolescent stress interact to alter NMDA receptor binding in the medial prefrontal cortex.
Schizophrenia is thought to arise due to a complex interaction between genetic and environmental factors during early neurodevelopment. We have recently shown that partial genetic deletion of the schizophrenia susceptibility gene neuregulin 1 (Nrg1) and adolescent stress interact to disturb sensorimotor gating, neuroendocrine activity and dendritic morphology in mice. Both stress and Nrg1 may have converging effects upon N-methyl-D-aspartate receptors (NMDARs) which are implicated in the pathogenesis of schizophrenia, sensorimotor gating and dendritic spine plasticity. ⋯ In the IL, whilst stress tended to increase NMDAR binding in WT mice, it decreased binding in Nrg1 HET mice. However, in the DG, stress selectively increased the expression of NMDAR binding in Nrg1 HET mice but not WT mice. These results demonstrate a Nrg1-stress interaction during adolescence on NMDAR binding in the medial prefrontal cortex.